Almost 100 days after President Barack Obama took office, former Sen. Arlen Specter deserted the Republican Party and joined forces with the Democrats.

What convinced him to switch paths?

Some pundits speculate the blame lies squarely on Vice President Joe Biden, Specter’s former colleague in the Senate.

The veteran politician told a Houston fund-raiser that he had actively spent the first 100 days of the Obama administration convincing his pal to turn away from the party he had professed for 44 years.

Biden denied he alone convinced Specter to switched allegiances, but admitted he called Specter over 14 times during a 10-week-period. As Politico reports:

Biden's argument over the past two months was plain, according to the White House official: “Your party has left you.”

"It's no longer a place for a moderate, pragmatic Republican," he'd tell Specter, arguing that when Specter was elected in 1980, the GOP had a lot of moderate Republicans, but that the Democratic Party was more in line with the senator's views on health care, the economy and foreign policy, the official said.

Herein resides a defining characteristic of Biden’s vice presidency: his ability to use his connections to quietly influence policy and politics. His reputation for political suaveness runs headfirst into the other characteristic of his public persona -- that of an outspoken Democrat who says the wrong words in front of a live mic.

In August, Biden told a rally gathered in Danville, Va., of largely African American supporters that the election of Republican candidate Mitt Romney would “put y’all back in chains,” prompting immediate criticism from the GOP for his choice of words.

The gaffes don’t stop there. On Tuesday, Biden called out the Romney campaign for planning to raise taxes on a middle class “that has been buried the last four years” – a point which Republicans called a “stunning admission” regarding the consequences of Obama’s presidency.

In public, Biden’s words have created so much commotion that some, including former GOP candidate Sen. John McCain, have speculated it would be wise for Obama to replace him.

Behind closed doors however, Biden has worked magic.

In 2010, Biden secured votes to ratify the New START nuclear arms treaty with Russia. During the debt ceiling crisis last year, it was Biden’s last minute bargaining with Mitch McConnell that helped seal the deal that saved the U.S. from economic catastrophe and plain embarressment.

He has also served as a behind-the-scenes advisor for Obama by using his experience as the former chair of the Senate Committee on Foreign Relations to advise Obama on what course of action to take with the War in Afghanistan.

So which Biden will show up at the debates -- the political liability that shoots the Obama campaign in the foot, or the political guru that commands respect from both sides of the aisle?